Brent Mason, Mackenzie Consoer, Rebekah Perkins BBE 5543 November 8, 2011

 TMDL Overview  Watershed Background  Water Quality Standards  Loading Capacity  Monitoring and Implementation  Conclusion

Clean Water Act Section 303 (d) requirements:  Every 2 years states publish a list of “impaired” waters  TMDL report must be developed for all waters on the impaired waters list TMDL Requirements:  Provides a calculation of the maximum amount of a pollutant that a water body can receive and still meet water quality standards  Sums the loads of a single pollutant from all point and non point sources

Wild Rice River watershed:  Encompasses just over 1 million acres  Flows Across 5 Minnesota counties  Lies within three eco-regions  Impaired for Turbidity from the confluence of the South Branch of the Wild Rice River to the Red River  Impaired section of River is miles in length and is located entirely within Norman County.

 Lower reach of Wild Rice River lies within the Lake Plain from Glacial Lake Agassiz  Extremely Flat with level deposits of lake sediment  Lower Wild Rice River is contained by low banks and has high sinuosity  Soils tend to be clays with low permeability and low internal drainage  Cropland dominates the land use of the Lower Wild Rice River  Upland is heavily drained by both ditch and tile systems

Designated Beneficial Use:  Water body is classified as both 2B and 3B water  Chose class 2 waters: aquatic life and recreation **Higher standards Turbidity:  25 NTU standard for natural water bodies  Surrogate measurement for Total Suspended Solids (TSS) and Suspended Sediment Concentration (SSC)

 Clarity of water  Caused by sediment, micro- organisms, dissolved material, and organic matter  Measurement of amount of light scattered  Measured with dimensionless unit of NTU  Blocks sunlight that fish and plants thrive on  Degrades aesthetic appeal of water body Lenntech.com Fishschooled.blogspot.com

 Turbidity is dimensionless and cannot be used to determine sediment loads  Relationship between Turbidity and SSC needed to be derived  Using paired turbidity and SSC data, simple regression analysis was used to create a relationship between the two variables  Using this relationship: 25 NTU = 38 mg/L SSC

o Majority of samples are at low flows and low turbidity o Limited amount of data

 Major inconsistencies between turbidity meters  Turbidity relationship only based on one year of data and primarily at one location **Depending on how the make up of the sediment changes throughout this watershed, this relationship can vary greatly  The majority of the data was taken during low flows or winter months

-Only 2 sites -Underrepresented Low Flow Zone

WLA TMDL = WLA + LA + MOS + RC o Four Identified Potential Sources: 1. Municipal Wastewater Treatment Facilities (WWTFs) 2. Construction Activities 3. Industrial Facilities 4. Concentrated Animal Feeding Operations (CAFOs) Note: No MS4 permit requirements (stormwater) o All Require NPDES/SDS permit o Assumed Full Permit Compliance o Minor contributors to turbidity impairment

1.Municipal Wastewater Treatment Facilities (WWTFs) o NPDES/SDS permit = 45 mg/l TSS o Assume TSS values comparable to SSC o Similar is stream with high fine material (Gray et al, 2000) o Lower Wild Rice ~90% fine material (Macek- Rowland and Dressler, 2002) o Seasonal Discharge Windows o April-June and Sept-Dec o Assumes coincides with High Flows 1.5 tons/day for each flow zone, except low flows

 Loading Capacity for LOW FLOW ZONE very small  Permitted WWTF loads exceed total daily loading at low flows **Not possible because it is a component of total loads  Concentration – based on allocation to sources for low flow zone  Allocation = (flow contribution from a given source) x (45 mg/L TSS, the permit limit)

2.Construction Activities o WLA=estimated % of disturbed land= 0.17% o MPCA stormwater permit records 3.Industrial Facilities o 2 located in watershed o No accessible acreage data o Assumed same as Construction Activities (0.17%) 4.Concentrated Animal Feeding Operations (CAFOs) o 2 located in watershed o WLA=0 discharge, in accordance with permit Construction Activities + Industrial Facilities + CAFOs=.17% +.17% + 0% = 0.32% of TMDL within each Flow Zone

o No NPDES/SDS Permit Requirements o Major Load Contributors, occurs mostly at HIGH FLOWS o LA = Total Load Capacity-WLA-MOS o Primary Drivers in Wild Rice River Watershed o Upland Soil Erosion o Stream-Bank Erosion o Relative contributions? o Natural Processes LA TMDL = WLA + LA + MOS + RC magazine.noaa.gov

Margin of Safety (allocation uncertainty) o Four highest flow zones o Accounted for flow variability within each flow zone o Median flow-Minimum flow within each zone (standard calculation) o Low Flow Zone o Implicit MOS used (built into TMDL allocations) o Conservative assumptions o Discharge periods = High flows o Discharging below permit limits MOS TMDL = WLA + LA + MOS + RC

Reserve Capacity (future loading uncertainty) o Population Growth o 4/10 cities decline o 6/10 cities increase from 1.9% to 7.5% o WWTFs operating below loading limits, no planned expansion o RC = 0 RC TMDL = WLA + LA + MOS + RC

 Flow Zone Sample Representation  NPDES/SDS permit compliance  Assume TSS values comparable to SSC  Seasonal Discharge Windows Coincide High Flow  Land Disturbance % = Loading Allocation %  Natural Background Insignificant  RC = 0

Current Monitoring Activities  Red River Basin Watch  USGS flow monitoring and sediment analysis  MPCA milestone and condition monitoring Future Monitoring Plans  Future monitoring is being developed by the Wild Rice Watershed District with the assistance of its Flood Damage Reduction Team

Restoration Plan under development:  Focus of plan: Identify sources of sediment spatially  Funding for Implementation: Existing programs (Clean Water Legacy, Conservation Reserve Program, etc.)  Soil and Water Conservation District: Encourage the funding of programs that will reduce non point sources of turbidity

Best Management Practices (BMPs)  Filter Strips  Riparian Buffers  Grassed Waterways  Cover Crops  Conservation Tillage

 Requires collaborative effort by many individuals and organizations  Assumes land use practices do not change significantly  Restoration costs are estimated to be in the tens of millions of dollars  Restoration tools suggested will occupy many acres of valuable farmland.

 Turbidity and SSC were monitored  Numeric standard of 38 mg/L derived  Load duration curve developed to evaluate load exceedences  Monitoring and implementation plans being developed  Many assumptions were made but few assumptions had a significant impact on overall load calculations